cdec data url and format changed

[dschneiderch]

need to update import_data function for cdec stations

new cdec url format
downloadURL=paste0('http://cdec.water.ca.gov/dynamicapp/req/CSVDataServlet?Stations=',site_id,'&SensorNums=82&dur_code=D&Start=1900-01-01&End=',strftime(simdate,'%Y-%m-%d'))